Internal combustion engine



Oct. 31, 1933. TlBBETTs INTERNAL COMBUSTION ENGINE Filed Nov. 5. 1930 Patented Oct. 31, 1933 PATENT OFFICE INTERNAL coMBUs'rIoN ENGINE Milton Tibbetts, Detroit, Mich,

assignor to Packard Motor Car Company, Detroit, Mich., a corporation of Michigan Application November 6, 1930. Serial No. 493,72

9 Claims. (01. 121 -194) -This invention relates to internal combustion engines and more particularly to crank case and cylinder structures.

- It isa general object of the invention to provide a novel and improved form of internal combustion engine. p l

, More particularly itsis an object of the invention to provide inkan internal combustion engine a novel mechanism for securing cylinders with the crank case.

mechanism for securing cylinders with the crank case of an internal .combustion engine in a mannersuch that there will be no localized stresses developed inthe crank case due to forces resulting from engine operation.

' A further object of my invention isto provide an internal combustion engine of the-radial type in which endless band meansclosely encircle the crank case and aremounted upon trunnions on the cylinders.

These and other objectsof the invention will appear fromthe following description taken in connection with the drawing, which form a part of this specification, and in which: I

Fig. 1 is a front elevational view of aradial aeroplane engine with the propeller blades removed; f V

Fig. 2 is a vertic'alsectional view of the same taken'on line 2-'-2 of Fig. l;

Fig.3 is a sectional view through two of the cylinders taken on line 3--3 of Fig. 1;

.Fig. 4 is a fragmentary elevational-view illustrating .12, modified form of cylinder securing meansy Fig. dis a fragmentary sectional view of the modified formof connecting means and its mounting. i

, Referring now to the drawing by characters of reference, 10 represents a barrel-type of crank case from which a plurality of cylinders 11 extend manna. The cylinders are each formed with a circular flange 12 which bears against a *fiattened portion of the outer face of the crank case, and the skirtportionsl3 of the cylinders 'extend through openings formed through the flattened portions of the crank case.

. A' crank shaft 14 extends axially through the- 1'5 18 while a pair of spaced reinforcing walls 19 Another objector" my invention is to provide such as pins 26.

and 20 extend across the interior of the crank case on each side of the crank throw and in a plane with the flanges 12 of the cylinders. The reinforcing wall 20 is removable and is secured within the crank case by bolts 21 while the reinforcing wall 19 is preferably cast as an integral part of the crank case. I 1

It will be seen that the cylinders 11 are provided with flanges 12 which provide the sole axialv contact for the cylinders with the crank case and 5 thus any forces developed in the cylinders when the engine is in operation will be transferred to the crank case through the contacting area of the flanges therewith. As a means of securing the cylinders against the crank case so that there will be no localized stresses, I provide a pair of endless band means which in the preferred form consist of a plurality of angular links 22, the adjacent ends of which are joined by turnbuckles 23. Each of the cylinders is formed with a pair of oppositely disposed trunnions 24 which are preferably arranged at the frontand rear of each cylinder and in a similar manner throughout the structure and each of the angular links is provided with an eye portion 25 which is pivotally mounted upon a trunnion and is secured against axial displacement therefrom by suitable means The trunnions are'spaced outwardly of the cylinder flanges 12 but relatively close thereto.

After the pair of endless band means have been assembled upon the trunnions on each end of the cylinders, the turnbuckles are adjusted to place each band means under a tension which is greater than that developed therein by forcesto which it is subjected when the engine is in operation in order to hold the cylinder flanges '12 against their seats on thefcrank case under all operating conditions and with the desired factor of safety. In this manner the crank case is entirely relieved of any tensile stress resulting from the expansion of the explosive mixture in themginecylinders during operation, as the tendency of the explosive forcesto move the cylinders radially outwardly is not transmitted to the crank case as would be the condition'if bolts were employed to secure the cylinders to the crank case. It will be seen that with this arrangement of securing means the forces developed in one cylinder'will be transferred circularly of the band 10 means. aroundthe crank case'so that all. forces. developedduring operation of the engine in any cylinder will be transmitted in'a circular direc-' tion through the band means to the trunnions and through the baseof the cylinders and. their ;l

cifically claim, I do not that my invention is'lii flanges to the crank case. With this arrangement of transferring stresses I am able to construct the cylinders and crank case of relatively light and thin metal so that the weight of the crank case and cylinder construction can be light and at the same time rugged enough to withstand the high compression and explosion forces developed by a Diesel type of engine. The reinforcing Walls 19 and 20 are preferably arranged in a plane with the trunnions and the endless bands so that the circumferential wall of the crank case will be interiorly supported. As a result there will be no localized stresses such as are present when bolts are used to secure'the cylinders to the crank case and a very rugged lightweight structure can be made which is capable of withstanding high pres.-

sures. I

In Figs. 4 and 5 I have illustrated a second form of cylinder securing means wherein the endless band means 30 is formed as an integral structure instead of being made in sections.- This endless structure includes eye portions 31 which correspond to'the eye portions 25 of preferred form ofeonnecting means and such e es are mounted upon eccentric bearings 32 which'are adjustably carried by the trunnions 24. The eccentric bushings are provided with a hexagonal head 56 which can be engaged by suitablemeans and rotated to place the eccentric bushings in desired adjusted position. In this embodiment I have illustrated keys 33 which can be inserte in regis ering grooves formed the adjacent surfaces of the trunnions and the eccentric bushings. It will be seen that rotation of the eccentric bushings 32 will'increase or decrease the tension or" th endless band means so so that by regulating the eccentric bushings th endless band means can be placed in any desired tension.

In order to retain the cylinder against crank case when the endless band means is nioved, I providea clamp 34 arranged'inte diate adjacent cylind rs which can be positioned the to engage the flanges 12 the bolt 35 loosened, the bolt being screwed into the crank 'case.

d when sition and ibed in some detail a r ntion, W i c it to be understood of the construction, as it will be apparentthat changes may be made therein without departing of my invention.

the crank case, trunnions on the cylinders beyond the bearing portion, and a pair of sectional, contractible and expansible band structures surrounding the crank case, each section of the band structi being. anchored on a trunnion the ends being joined by adjustable connectors for placing the structures in tension greater than ich ed to the exact details that developed therein by the forces present during operation of the engine.

3. In an internal combustion engine, a crank case, cylinders having a portion bearing against the crank case, band means extending around the crankcase and composed of sections joined by adjustable tension connectors, and trunnions extending from the Walls of the cylinders, said see tions of the band means being pivotally anchored n the trunnions.

4. In an internal combustion engine, a crank case, a plurality of cylinders extending radially from the crank case, flanges integral with the cylinders and bearing against the crank case,

trunnions projecting from opposite sides of the cylinders adjacent the flanges, anda pair of band means closely surrounding the crank case on! opposite sides of'the cylinders and in high initial tension, each pair of band means comprising a plurality of sections pivotally anchored on the cylinder trunnions and adjustable means case a plurality of radial cylinders bearing against the crank case, oppositely disposed trunnions projecting from the cylinders adjacent the:

bearing portion thereot and endless band means for securing the cylinders to the crank case, said band means comprising links each pivotally I mounted on a trunnion, and turnbucklesconnecting the adjacent ends of the links. c 7. In an internal combustion engine, aycr'ank case, a plurality of radial cylinders bearing against the crank case, oppositely disposed trunnicns rojecting-froin" the cylinders adjacent the bearing portion thereof, an adjustable eccentric bushing on each of the trunnionsyandend-- less band means encircling the crank case and mounted onthe bushings, the rotation of .the bushings varying the tension of the band means.

8. In an internal combustion engine, a. crank case, radial cylinders-bearing against the crank case, oppositely disposed trunnions extending from the cylinders in a'similar manner, adjust able eccentric bushings onthe trunnions','endless band means encircling the crank-case and inounted'on the bushings,-. and means for securing the bushings in desired position-of adjustinent, the position of the. bushingsdeterniining the tension of the endless band means.

.9; In an internal combustion engine,.th'e comtion thereof bearing against the crank casefoppositely disposed trunnions projecting from the cy inders," a pair of endlessband means disposed on opposite sides of the cylinders and anchored.

on the trunnions, and means associated witheach of said band means adjustable to establish tension" in the bandmeans greater than that therein by engine explosion forces- 'MILTON TIBBETTS.

developed bination of a crankcase, cylinders having a 'por- 

